Invirase is only approved for use in combination with other medications to treat HIV and AIDS. Specifically, it should always be used with ritonavir, a medication that improves its effectiveness. Although Invirase cannot cure HIV or AIDS, it can block a process that the HIV virus needs in order to multiply. Possible side effects include nausea, diarrhea, and fatigue.
What Is Invirase?Invirase® (saquinavir mesylate) is a prescription medication approved to treat HIV and AIDS. It should always be combined with ritonavir (Norvir®), another medication that improves the effectiveness of Invirase. Invirase is only approved for use with ritonavir, plus other HIV or AIDS medications.
At one point, Fortovase® (a similar product that also contained saquinavir) was also available. However, this medication is no longer available.
How Does Invirase Work?Invirase belongs to a group of HIV medications known as protease inhibitors. These medicines work by blocking a process that the HIV virus needs in order to multiply.
HIV (human immunodeficiency virus) is the virus that causes AIDS. Like other viruses, it must use a person's own cells to reproduce. Once inside an infected cell, the HIV virus uses the cell to make DNA, which enables it to make new HIV viruses that can spread to other cells. The DNA is made into long strands that must be clipped into shorter, usable strands using enzymes called proteases.
Invirase stops protease enzymes from clipping DNA into short strands. Because the long, unclipped DNA strands cannot be used to make new viruses, this helps stop the spread of HIV to other uninfected cells. Invirase is not a cure for HIV or AIDS, however. Although it can help stop HIV from infecting healthy cells in the body, it does not help cells that have already been infected with the virus.
Invirase is always used in combination with ritonavir, which increases the level of Invirase in the blood, helping it work better. This is known as "boosting." Ritonavir is used to boost several different HIV medications.